450C won't go into low or reverse

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desertozzy
MC crawler
MC crawler
Posts: 1
Joined: Fri Jan 31, 2020 1:26 pm

450C won't go into low or reverse

Post by desertozzy » Fri Jan 31, 2020 6:49 pm

I have an '82 450C with constant mesh transmission. It runs and drives ok with the reverser in high, but won't move in low or reverse. I opened the range change compartment and it seems to move into low and reverse ok. What to check next?

The back story to this is that the problem started right after I drained and replaced all the hydraulic fluid to replace a bad hydraulic hose. When I started back up it would only go in high. Maybe unrelated?

Jim B
350 crawler
350 crawler
Posts: 2080
Joined: Sun Nov 05, 2017 11:36 am
Location: western Maine

Re: 450C won't go into low or reverse

Post by Jim B » Fri Jan 31, 2020 9:23 pm

Welcome to the board. Just so you know this post will likely get moved to the late model board. That is where the 350s, 450s, and later models belong.

The hydraulic reservoir is the tank under the right armrest. The transmission oil reservoir is the case of the transmission. Totally separate systems. Is the transmission oil level correct on the dipstick?

Your crawler should have what is called the HLR transmission. The High, Low, and Reverse are provided by hydraulic clutches supplied with oil by a pump in the transmission. The 4 speeds are provided by the gear section behind the HLR.

You may have hydraulic problems in the HLR which will require diagnosis and pressure checks. Do you have the John Deere technical manual TM1102? It is the guide you need to do the proper checks in the right order. Using the manual, then asking questions the guys here can help you with little details. If you don't have the manual, send Lavoy an email (postmaster@jdcrawlers.com). He has some manuals in his store, which provides this site for us to use. If he can't help you with the right manuals post back and the guys can help you find other sources. You should also have the Operator's manual OMT71338. It has info on lubrication and normal maintenance. You can purchase a hard copy of the parts catalog PC1420 or use the on line ones at jdparts.com.

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